(a) Field of the Invention
The present invention relates to a reverse gravure offset printing method and apparatus, and more particularly, to a reverse gravure offset printing method and apparatus using a disposable cliche, which do not require cleaning of the cliche and do not require a large quantity of high-definition cliches because the cliche used in reverse gravure offset printing can be discarded after used once or several times and replaced with a new one, thereby achieving cost reduction.
(b) Description of the Related Art
In general, reverse gravure offset printing includes a base 120 applied with conductive ink I, a cliche CL, a roller 110, and a substrate 140, as shown in FIG. 2.
The roller 110 is brought into contact with the base 120 to transfer the conductive ink I from the base 120 to the roller 110.
Afterwards, the roller 110 is brought into contact with the cliche CL to peel off an unnecessary pattern I-2 on the roller 110 to the cliche CL, and then the roller 110 is brought into contact with the substrate 140 to set a necessary pattern I-1 on the substrate 140 (see FIG. 3 and FIG. 4)
The cliche L has a plurality of protrusions CL2. The protrusions CL2 are brought into contact with the roller 110 to transfer the unnecessary pattern I-2 to the protrusions CL2, as described above.
At this point, the conductive ink I is not transferred to recesses CL1 between the protrusions CL2. As a result, the necessary pattern I-1 remains on the roller 110.
The roller 110 carries out the above-described process while being rolled and moved by a roller driver 160.
This is well-known and disclosed in detail in Patented Invention No. 975,094, and hence a detailed description thereof will be omitted.
Unexplained reference numeral 150 denotes a table supporting the base 120 and the cliche CL.
However, the conventional reverse gravure offset printing has the following problems.
First, the cliche CL needs constant cleaning. As described above, the roller 110 is brought into contact with the cliche CL to peel off the unnecessary pattern I-2, during which the conductive ink, organic substances, alcohol, etc. remaining on the cliche CL have to be cleaned off.
However, cleaning of the cliche CL generates a large amount of waste solution, as well as requiring much effort and time.
Second, the printing process has to continue even during cleaning of the cliche CL, and hence it is necessary to prepare a large quantity of cliches CL in advance.
However, the above-described conventional cliche CL requires high definition and is made of metal, and therefore it costs a lot to prepare a large quantity of cliches CL in advance, as described above.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.